Improvement in steam slide-valves



1. YouNMAN'.

i Steam Slide-Valves. No.149,822. Pa:en.1edApri|14,1a74.

UNITED STATES PATENT OFFICE.

JACOB YOUNGMAN, OF SUNBURY, PENNSYLVANIA.

IMPROVEMENT IN STEAM SLDEVALVES.

Specification forming part of Letters Patent N0.149,S22, dated April 14,1874', application iil'ed March 16, 1374.

To all whom it may concern:

Be it known that I, J ACCB YCUNGMAN, of Sunbury, in the county ofNorthumberland and State of Pennsylvania, have invented a v new anduseful Improvement in Steam Slide- Valves, used in locomotives andstationary engines; and I do hereby declare that the following is afull, clear, and exact description located within the steam-chest, thediagraml marked A being a portion ofthe top of the steam-chest, thatmarked B B being the improved valve. Fig. 3 is a transverse vertical ysection of the same, A A A representing the steam-chest, B B the valve.Fig. 2 is a longitudinal representation of metallic packing, similarletters in each of the several figures indicating corresponding parts.

My invention relates to an improvement in the well-known steamslide-valve, commonly known as the D-valve, which, in height, occupiesabout one-half of the space of the steamchest, and has bearing upon itthe pressure of the steam forced from the boiler within the inclosureofthe chest.` The nature of my invention consists in occupying` the wholeof the chest vertically, with a' combination of spiral springs, metallicor other packing, and an adjustable cap, a part of which is marked a a,as is represented in Figs. 1 and 3, in connection with `the ordinaryD-valve, thus preventing the steam from occupying that part of the chestwhich exists above the ordinary valve, thereby avoiding the pressurementioned. The purpose of my combination of spring, cap, Ste., is torender the valve elastic and flexible, to overcome the difficulties fromthe expansion of the metal when heated, which otherwise would cause thefastening of the valve between the top of the steam-chest and the seat,and at the same time renders every joint steamtight, thus preventing thesteam from getting on top of the valve. Its flexibility, produced bybeing thus formed, also allows the cap to yield, which is necessary whenair is being pumped into the chest through the motionof the piston-headproduced by the impetus of the engine when the steam is shut off.

To enable others skilled in the art to make and use my invention, I willproceed to describe its construction and operation.

E, Fig. 3, is a screw-bolt attached to thc top of the valve, and passesthrough the adjustable cap, marked F, upon which the nut G operates. Iis metallic packing, and J is a spiral spring. "B, Fig. 1, is an openingin the top of the steam-chest of suflicient extent to allow the nut G,Fig. 1, to move the full extent of the movement of the valve, and forthe purpose of giving access to the nut with a wrench whenever occasionrequires.

The packing, Fig. 2, consists of four separate pieces of soft metal orother suitable material, formed in the shape of an ordinary carpenterssquare, which are placed between the cap mentioned and the top of thevalve, laid one on top ofthe other, so as to break joint, to the effectthat when the steam is admitted into the steam-chest the packing ispressed downward and inward, closing the joints against the shoulder ofthe cap, (see Fig. 3, marked 3,) and the top of the valve, (see Fig. 3,marked 4,) thereby preventing the steam from pressing upon the Valve.'lhis packing lies loose when the steam is off, and is kept in place bya number of lugs descending from the adjustable cap, one of which isseen in Fig.l, marked 5, and two in Fig. 3, marked 6 and 7.

I claim as my invention- The combination, with the ordinary valve, of abolt and nut, and a cap, spring, and packing, as described, and anopening in chesthead, constructed as and forthe purpose set forth.

JACOB 'YCUNGMAE

